Curcuminoids are curcumins and derivatives of curcumins with different chemical groups. These compounds are polyphenols and produce yellow color. The characteristics of many curcuminoid compounds are unsuitable for drug design since they have poor solubility in water at acidic and physiological pH, and also hydrolyze rapidly in alkaline solutions. Therefore, curcumin derivatives are synthesized to increase their solubility and hence bioavailability (Studies on curcumin and curcuminoids XXXI. Symmetric and asymmetric curcuminoids: Stability, activity and complexation with cyclodextrin. Author(s): Tomren M A (Tomren, M A.), Masson M (Masson, M), Loftsson T (Loftsson, T.), Tonnesen H H (Tonnesen, H. Hjorth). Source: INTERNATIONAL JOURNAL OF PHARMACEUTICS 338 (1-2): 27-34 Jun. 29, 2007). Curcuminoids are soluble in dimethyl sulfoxide (DMSO), acetone and ethanol (Formulation and characterization of curcuminoids loaded solid lipid nanoparticles. Author(s): Tiyaboonchai W (Tiyaboonchai, Waree), Tunpradit W (Tunpradit, Watcharaphorn), Plianbangchang P (Plianbangchang, Pinyupa). Source: INTERNATIONAL JOURNAL OF PHARMACEUTICS 337 (1-2): 299-306 Jun. 7, 2007 but are poorly soluble in lipids. It's possible to increase their solubility in aqueous phase with surfactants or co-surfactants (Antioxidant activities of curcumin, demethoxycurcumin and bisdemethoxycurcumin. Author(s): Jayaprakasha G K, Rao L I, Sakariah K K Source: FOOD CHEMISTRY 98 (4): 720-724 2006): There have been synthesized curcumin derivatives that could possible be more potent than curcumin. Most common derivatives have different substituents on the phenyl groups (Formulation and characterization of curcuminoids loaded solid lipid nanoparticles. Author(s): Tiyaboonchai W (Tiyaboonchai, Waree), Tunpradit W (Tunpradit, Watcharaphorn), Plianbangchang P (Plianbangchang, Pinyupa). Source: INTERNATIONAL JOURNAL OF PHARMACEUTICS 337 (1-2): 299-306 Jun. 7, 2007. Now there is an increasing demand for demethoxycurcumin and (curcuminoids) because of their recently discovered biological activity (Antioxidant activities of curcumin, demethoxycurcumin and bisdemethoxycurcumin. Author(s): Jayaprakasha G K, Rao L I, Sakariah K K Source: FOOD CHEMISTRY 98 (4):720-724 2006).
Natural curcuminoids are those extracted from the Curcuma longa plant and they are majorly comprised of 3 constituents a). Curcumin b) demethoxycurcumin c) bisdemethoxycurcumin. Several studies have shown that their pharmacological effects are comparable to those of corticosteroids and non-steroidal anti inflammatory drugs.

Curcumin (FIG. 1B) was isolated in 1815 and structurally defined in 1910. Other curcuminoids isolated from Curcuma longa include demethoxycurcumin (FIG. 1 C), bisdemethoxycurcumin (FIG. 1 D), a cis-trans geometrical isomer of curcumin (FIG. 1 E), and cyclocurcumin (FIG. 1 F)
Thus, in the view of its structure it is evident that the solubility of curcuminoids is very poor in aqueous solutions. Thus quite a number of studies are in progress with regard to increasing its solubility in water and the prior art relevant in this regard is listed below:
PCT/US2007/005829 describes Curcuminoid formulations having enhanced bioavailability are provided and comprise a curcuminoid, antioxidant, glucuronidation inhibitor, and water-soluble, pharmaceutically acceptable inhibitor. A method of treating Alzheimer's and other age-related diseases by administering such a composition is also provided and also a method to solubilize curcuminoids through nanoemulsions.
PCT/KR2004/000529 describes a method for solubilization of curcumin and dispersion into water. The method prepares a water-soluble curcumin by covalent-bonding of sugar with the curcumin, thereby making the curcumin, which was insoluble in water, into a water-soluble curcumin.
Biji T Kurien et al have described yet another process to solubilize curcumin through the use of heat energy. (Improving the Solubility and Pharmacological Efficacy of Curcumin by Heat Treatment—ASSAY and Drug Development Technologies, Aug. 1, 2007, 5(4): 567-576. doi:10.1089/adt.2007.064)
BISHT et al have encapsulated the curcumin particles using nanoencapsulation terming it ‘nanocurcumin’. Polymeric nanoparticle-encapsulated curcumin (“nanocurcumin”): a novel strategy for human cancer therapy Journal of Nanobiotechnology Apr. 17, 2007, 5:3
TOMREN M A Studies on curcumin and curcuminoids XXXI. Symmetric and asymmetric curcuminoids: Stability, activity and complexation with cyclodextrin. Author(s): Tomren M A (Tomren, M A.), Masson M (Masson, M), Loftsson T (Loftsson, T.), Tonnesen H H (Tonnesen, H. Hjorth). Source: INTERNATIONAL JOURNAL OF PHARMACEUTICS 338 (1-2): 27-34 Jun. 29, 2007)
It is a well known fact that curcumin has very low bioavailability as it undergoes metabolism very rapidly and results in excretion of 98% of the curcumin. With only 2% of the compound absorbed by the body, it still brings about remarkable efficacy in the treatment of lot of diseases.
Although, the use of non-ionic surfactants has been discussed for solubilization purpose in the above mentioned literatures, they appear to be in a different context. The surfactants used have been done so in order to make emulsions and the likes and not for directly solubilizing curcuminoids.
Therefore, the current invention aims to enhance the aqueous solubility of the highly lipophillic polyphenolic compounds such as curcuminoids using non-ionic surfactants and a non-ionic cosolvent at a specific concentration together with the help of sonar energy.